Generally, brain waves mean the electrical flow when signals between cranial nerves are transmitted, and are divided by slow waves and fast waves. For example, delta waves which are slow are formed in case for a man to sleep, and beta waves which are fast are formed in case for a man to be active, and alpha waves which approximately have a medium velocity are formed in case for a man to be meditative. The features of brain waves as being generated above are below described.
Delta waves have the frequency range from 0.5 Hz to 4 Hz, and have unconsciousness state level. The delta waves are presented in a deep sleep or a comatose state, and are especially presented in babies' brain waves.
Theta waves have the frequency range from 4 Hz to 8 Hz, and have internal consciousness state level. The theta waves are presented in an emotionally stable state or in case for a man to begin to sleep, and are also presented in an initiative state, a relaxation state.
Alpha waves have the frequency range from 8 Hz to 14 Hz, and have internal consciousness state level. The alpha waves are presented in a relaxation state or in a tranquil state, and are also presented in a peaceful state physically and mentally.
Beta waves have the frequency range from 14 Hz to 30 Hz, and have consciousness state level. The beta waves are presented in a conscious activity state, for example, waking up, talking, etc, and are especially presented in an anxious state or a tense state.
Gamma waves have the frequency range from 30 Hz to 50 Hz, and have consciousness state level. The gamma waves are presented in case to watch exiting sports games or to solve very difficult mathematics problems.
Accordingly, it is profitable to let alpha waves released in a brain so as to mitigate tension such that may enhance the health.
Recently, a lot of beds which are capable of being inclined with fixing ankles have been developed so as to support health. These beds operate to face a head downward and legs upward so as to flow blood to head part. In accordance with that, alpha waves are presented in a body, and pulse waves by heart become stable, and blood pressure is dropped such that user may become in a stable state mentally and physically.
However, traditional beds have a deficiency that traditional beds and methods thereby are not systematical because both the inclination and the duration are controlled based on user's experience.
Also, they have a deficiency that users like old aged men and children cannot deal with a sudden change because traditional beds and methods thereby have no standard to incline those.